Lamb Burger with Pomegranate Seeds

Name: Lamb Burger with Pomegranate Seeds
Prep time: 30 min
Cook time: 3 h
Total time: 3 h 30 min
Cuisine: American
Ingredients: 1 leg of lamb, about 1.2kg; salt; pepper; 3 tbsp olive oil; 2 onions; 4 cloves; 1 star anise; 1 cinnamon stick; 1 bay leaf; 1/2 tsp allspice powder; 100ml red wine; 400g diced tomatoes; 150g tomato puree; 125ml beef stock; 4 burger buns; 4 tbsp butter; rocket; 40g pomegranate seeds